Migration education and literacy in Brazil with special reference to the North East and Sao Paulo

<p>Cells were cultured, incubated with NECA and assayed for mRNA expression by quantitative realtime PCR as described in Materials and Methods. Data given in A and B are means of five replica culture dishes ±SEM. Two repetitions of the experiment gave similar results. Data given in C are means of 3 different experiments done in four replica culture dishes. *p<0.05, ** p<0.01, *** p<0.001, student’s t-test, two-tailed.</p

Adenosine Receptors Differentially Regulate the Expression of Regulators of G-Protein Signalling (RGS) 2, 3 and 4 in Astrocyte-Like Cells

<div><p>The “regulators of g-protein signalling” (RGS) comprise a large family of proteins that limit by virtue of their GTPase accelerating protein domain the signal transduction of G-protein coupled receptors. RGS proteins have been implicated in various neuropsychiatric diseases such as schizophrenia, drug abuse, depression and anxiety and aggressive behaviour. Since conditions associated with a large increase of adenosine in the brain such as seizures or ischemia were reported to modify the expression of some RGS proteins we hypothesized that adenosine might regulate RGS expression in neural cells. We measured the expression of RGS-2,-3, and -4 in both transformed glia cells (human U373 MG astrocytoma cells) and in primary rat astrocyte cultures stimulated with adenosine agonists. Expression of RGS-2 mRNA as well as RGS2 protein was increased up to 30-fold by adenosine agonists in astrocytes. The order of potency of agonists and the blockade by the adenosine A2B-antagonist MRS1706 indicated that this effect was largely mediated by adenosine A2B receptors. However, a smaller effect was observed due to activation of adenosine A2A receptors. In astrocytoma cells adenosine agonists elicited an increase in RGS-2 expression solely mediated by A2B receptors. Expression of RGS-3 was inhibited by adenosine agonists in both astrocytoma cells and astrocytes. However while this effect was mediated by A2B receptors in astrocytoma cells it was mediated by A2A receptors in astrocytes as assessed by the order of potency of agonists and selective blockade by the specific antagonists MRS1706 and ZM241385 respectively. RGS-4 expression was inhibited in astrocytoma cells but enhanced in astrocytes by adenosine agonists.</p></div

Concentration-response relationship (A) and time course (B) of the effect of NECA on expression of RGS2 protein in cultured rat astrocytes.

<p>Cells were cultured, incubated with NECA (concentrations as indicated in A; 1 μM in B) and assayed for protein expression by western blotting as described in Materials and Methods. Shown are the results of one typical experiment, one repetition gave similar results.</p

Effects of adenosine agonists and the adenosine A2A and A2B receptor antagonists, MRS1706 (500nM) and ZM241385 (1μM), on the expression of mRNA of RGS2 (A,B,C), RGS3 (D,E,F) and RGS4 (G) in rat astrocytes.

<p>Cells were cultured, incubated with agonists/antagonists and assayed for mRNA expression by quantitative realtime PCR as described in Materials and Methods. Data given are means of 4 (NECA, CGS21680), 3 (CPA, IB-MECA, CGS21680/ZM241385) or 5 (NECA/MRS1706) experiments each done with 4 replica culture dishes. * p<0.05, ** p<0.01, *** p<0.001, student’s t-test, two-tailed.</p

Effects of adenosine agonists and the adenosine A2B receptor antagonist MRS1706 (500 nM) on the expression of mRNA of RGS2 (A,B), RGS3 (C,D) and RGS4 (E,F) in human astrocytoma cells U373 MG.

<p>Cells were cultured, incubated with agonists/antagonists and assayed for mRNA expression by quantitative realtime PCR as described in Materials and Methods. Data given are means of 5 experiments (NECA, NECA/MRS1706) or 2 experiments (CPA, IB-MECA, CGS21680) each done in five replica culture dishes.* p<0.05, ** p<0.01, *** p<0.001, student’s t-test, two-tailed.</p